When I don't have any mods or custom/normal plans i can't load I'm getting an error Zone 'zm_levelcommon not found.
Please help. I'm an important person. but everyone ignores me please help เบทฟิก

if you have installed your game via steam u just have to check the game data for errors with steam

You can verify the game files by right-clicking the entry in your Steam Library, selecting properties.
 
Once your in the properties, select local files, and click "Verify Integirty of Game Files".
 
Let me know if this helped